Upholstery system

ABSTRACT

A chair in which an upholstered inner seat and back matingly fit over a supporting seat and back with integrally formed projections on the supporting seat and back snapping into integrally formed receiving apertures in the inner seat and back. The supporting seat and back include overlapping channel portions to facilitate joining them in an aligned, continuous appearing manner.

[ Sept. 23, 1975 United States Patent Baker et al.

Hoven et a1. Oehmig............ Caruso....'.... Fulks et a1. Massaceesi Hurnick UPI-IOLSTERY SYSTEM [75] Inventors: Richard H. Baker; Robert C.

Clawson, both of Grand Rapids. Mich.

Primary Examiner-James T. McCall Attorney, Agent. or FirmPrice, Heneveld, Huizcnga & Cooper [57] ABSTRACT A chair in which an upholstered inner seat and back matingly fit over a supporting seat and back with integrally formed projections on the supporting seat and back snapping into integrally formed receiving apertures in the inner seat and back. The supporting seat and back include overlapping channel portions to facilitate joining them in an aligned, continuous appearing manner.

13 Claims, 16 Drawing Figures Mich.

297/DIG. 2 297/445 297/455; 297/DIG. 2

[73] Assignce: Steelcase lnc., Grand Rapids, 22 Filed: Apr. 22, 1974 [21] Appl. No.: 463,191

[52] US. Cl. 297/445; [51] Int. [58] Field of Search 297/460, 214, 446, DIG. 1, DIG. 2, 195,

[56] References Cited UNITED STATES PATENTS 2.824602 2/1958 Collins et 3,152,836 10/1964 US Patent Sept. 23,1975 Sheet 1 of7 3,907,363

FIG.

US Patent Sept. 23,1975 Sheet 2 of7 3,907,363

FIG.2

FIG.3

US Patent Sept. 23,1975 Sheet 3 of7 3,907,363

FIG. ,4

US Patent Sept. 23,1975 Sheet 4 of7 3,907,363

US Patent Sept. 23,1975 Sheet 5 of7 3,907,363

FIG. l0

US Patent Sept. 23,1975 Sheet 6 of 7 3,907,363

UPI-IOLSTERY SYSTEM BACKGROUND OF THE INVENTION The present invention relates to office furniture chairs, and particularly to an upholstery system therefor.

Upholstering office furniture seating is a very expensive operation in the overall manufacturing thereof. Most conventional upholstery systems require fitting some type of cushioning onto a supporting frame or other member or into an upholstery envelope, and then fitting the envelope over the supprting member and securing it thereto. To obviate the expense of this process, some manufacturers offer chairs in which an upholstery pad, including a composite of padding and covering material, is first prepared and then somehow fitted over a supporting shell or other member. Barecki U.S. Pat. No. 3,567,278, for example, discloses an upholstery pad which is secured to a supporting shell by means of bolts passing through the supporting shell and into nuts imbedded in the upholstery pad. Grant U.S. Pat. No. 3,647,260 discloses a pad having a special extrusion around the perimeter thereof which fits over the edge of the supporting shell.

These systems still require the use of some sort of special external fastener to secure the upholstery pad to the supporting shell. Such additional members create added eost, and can be difficult to work with.

SUMMARY OF THE INVENTION The present invention comprises a Chair in which the top and front lips of a formed plastic upholstered inner seat and back means matingly fit over the top and front edges of a formed plastic, supporting seat and back means, and one of the set of edges and set of lips includes integrally molded projections extending therefrom into receiving apertures in the other thereof. The upholstered inner seat and back means are thereby secured to the supporting seat and back means, which in turn are supported by suitable support means. The system is relatively easy to assemble and is relatively inexpensive in view of the fact that the projections and apertures are integrally molded into the formed plastic supporting seat and back means and formed plastic inner seat and back means when the respective seat and back means are formed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the chair of the present invention with the optional arms attached;

FIG. 2 is a perspective view of the stretcher and side rails of the chair with one arm attached;

FIG. 3 is a bottom plan view of the stretcher and side rails with one arm attached;

FIG. 4 is a perspective view of the chair-before the inner seat and back have been attached;

FIG. 5 is a cross-sectional view of the formed plastic seat taken generally along plane VV of FIG. 4;

FIG. 6 is a fragmentary bottom view of the front left hand corner of the chair, that portion being indicated genenrally by the arrow VI on FIG. 6;

FIG. 7 is a cross-sectional view of the formed plastic back taken generally along plane VIIVII of FIG. 4;

FIG. 8 is a fragmentary rear view of the upper left hand corner of the chair, that fragmentary portion being indicated generally by the arrow VIII shown on FIG. 4;

FIG. 9 is a fragmentary cross-sectional view of the overlapping portions of the formed plastic seat and backs taken generally along plane IXIX of FIG. 4;

FIG. 10 is a fragmentary, rear view of the portions of the seat and back which are shown in FIG. 9, said portions being shown separated in FIG. 10;

FIG. 11 is a generally rear perspective view of the formed plastic inner back covered with upholstery;

FIG. 12 is a generally bottom perspective view of the formed plastic inner seat covered with upholstery;

FIG. 13 is a fragmentary elevational view of the rear corner of the inner seat with the upholstery covering removed, said area being indicated generally by arrow XIII of FIG. 12;

FIG. 14 is a cross-sectional view of the inner seat assembled on the supporting seat, said cross section being taken generally along the plane XIVXIV of FIG. 4;

FIG. 15 is a cross sectional view of the inner back with upholstery covering fitted over the back, taken generally along plane XV-XV of FIG. 4; and

FIG. 16 is a fragmentary, cross-sectional view of the upper portion of the upholstered inner back taken generally along XVI-XVI of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the preferred embodiment, the chair (FIG. 1) includes an inner seat 60 and inner back 80 covered by suitable upholstering and cushioning 70 and 90 respectively which in turn are secured to a supporting seat and supporting back 50 by matingly engaging projections and apertures on matingly embracing lips and edges which will be more fully described hereinafter. The supporting seat 40 and supporting back 50 are mounted to a supporting frame assembly consiting of a stretcher 20 and side rails 30, stretcher 20 in turn being mounted on a suitable base 10.

Supporting seat 40 is formed by injection molding, of a polypropylene copolymer (approximately 13% polyethylene). Other plastics and other forming methods can be used. Seat 40 should be quire rigid, having a thickness of approximately 5/32 inch. When supported on side rails 30, supporting seat 40 serves to support a person seated in the chair (FIG. 4).

Supporting back 50 is formed by injection molding of a polypropylene copolymer (approximately 13% poly ethylene). Other plastics and other forming methods can be used. Back 50 should be quite rigid, having a thicknesss of approximately 5/32 inch. When supported on side rails 30, supporting back 50 serves to support a person leaning back in the chair. I

Seat 40 is rolled over along its front edge to define a front lip and includes three integrally molded buttons 47 projecting from its front edge 45 at spaced intervals therealong (FIGS. 4 and 14 Projecting from the rear edge 46 of seat 40 and three spaced integrally molded tabs 48. In a somewhat similar manner, four integrally molded buttons 58 project upwardly at spaced intervals from the rolled over top edge 56 of back 50 (FIGS. 4 & l6) and three integrally molded buttons 57 project outwardly from the rolled over bottom edge of back 50 (FIGS. 4 and 15). Each of the projecting buttons 47, 57 and 58 includes a post A and an enlarged head B so that an apertured portion of inner seat 60 or inner back 50 can be hooked thereunder. These integrally molded projecting buttons and tabs facilitate securement of the upholstered inner seat 60 and inner back to seat 40 and back 50 respectively. They are located on the parting line of their respective seat and back so that the use of cams in the molds for making these parts in minimized.

Inner seat 60 is preferably injection molded of basically the same plastic of which supporting seat 40 and supporting back 50 are made and has a thicknesss of approximately Vs inch. It should have sufficient thickness and rigidity that it will hold its shape when secured to supporting seat 40 and such that it will not be bent out of shape when it is covered with upholstery covering 70. It also has suff cient resilient flexibility that its lips will snap over the edges of supporting seat 40 and onto the projecting tabs 48 and buttons 47. It is molded to have a configuration conforming generally to the configuration of the inside of supporting seat 40 within well 42 (FIGS. 12 and 14).

Inner seat 60 is rolled over along its front edge to define a front lip 61 and it is turned sharply over along its rear edge to define a rear lip 62. Front lip 61 is shaped to matingly embrace the front edge 45 of supporting seat 40 and rear lip 62 is shaped to matingly embrace the rear edge 46 thereof. Front lip 61 includes three spaced holes 63 therein whose positions correspond generally to the front projecting buttons of seat 40. In this manner, inner seat 60 is secured along the front edge of supporting seat 40 by hooking the holes 63 over the heads of projecting buttons 47. Rear lip 62 includes three spaced slots 64 (FIGS. 12 and 13) spaced at intervals corresponding to the spacing of tabs 48, and each having a length corresponding approximately to the width of a tab 48, so that the rear of inner seat 60 is secured in place by snapping rear lip 62 over the rear edge 46 of supporting seat 40 with tabs 48 projecting into slots 64. Because the inner seat 60 has a configuration conforming to that of supporting seat 40, the fit of inner seat 60 over supporting seat 40 is tight. A slight tension is created in inner seat 60 when holes 63 and slots 64 are hooked over buttons 47 and tabs 48 respectively to thereby hold inner seat 60 in place on buttons 47 and tabs 48, and correspondingly on supporting seat 40.

Inner back 80 is similarly molded of basically the same plastic of which supporting seat 40 and supporting back 50 are molded and has a thickness of approximately /s inch. As with inner seat 60, inner back 80 must have sufficient thickness and rigidity to hold its shape during the covering process and to hold its shape when secured to supporting back 50. It also has sufficient resilient flexibility that its lips snap over the edges of supporting back 50 and onto the projecting buttons 57 and 58. Inner back 80 is molded to have a configuration corresponding generally to the configuration of the front surface of supporting back 50 in the area of the well 52 of back 50 (FIGS. 11 and Inner back 80 includes a rolled over bottom lip 81 and a rolled over top lip 82 which fit over the bottom edge 55 and top edge 56 of back 50 respectively. Bottom lip 81 is shaped to matingly embrace the bottom edge 55 of supporting back 50 and top lip 82 is shaped to matingly embrace the top edge 56 of supporting back 50. Top lip 82 includes four spaced holes 84 therein which receives the four spaced top projecting buttons 58 of back 50 and bottom lip 81 includes three spaced bottom holes 83 into which hook the heads of bottom buttons 57. FIG. 16 is particularly helpful in visualizing the manner in which the heads of the projecting buttons hook into and through the receiving holes. Because inner back 80 has a configuration conforming to that of supporting back 50, the fit of inner back 80 over supporting back 50 is tight. A slight tension is created in inner back 80 when holes 83 and 84 are hooked over buttons 57 and 58 respectively to thereby hold inner back 80 in place on buttons 57 and 58, and correspondingly, on supporting back 50.

Inner seat 60 is covered with a composite upholstery covering which includes a layer of cushioning material 71 and suitable upholstery material 72 (FIGS. 14). The cushioning material is adherred to the top surface of inner seat 60 with a suitable adhesive. Similarly, the upholstery 72 is adherred to the cushioning material 71 by suitable adhesive. Additionally, the upholstery 72 is wrapped around all of the edges of inner seat 60 and is attached along the upholstery edges to the rear surface of inner seat 60 by adhesive or possibly by other fastening means. FIG. 12, which is a view of inner seat 60 from the underside, is helpful in illustrating the manner in which the upholstery 72 is wrapped around the edges of inner seat 60 and attached to the rear of undersurface thereof.

Back upholstery covering composite 90 is similar and includes a layer of cushioning material 91 which is adherred to the front surface of inner back and a layer of upholstery 92 which covers the surface of cushioning 91. Upholstery 92 is wrapped around all of the edges of inner back 80 and is attached to the rear surface thereof. FIG. 11 is a generally rear perspective view of inner back 80 and shows the manner in which upholstery 92 is wrapped over its edges and adherred to the rear surface thereof.

The specific support assembly for supporting seat 40 and supporting back 50 does not specifically form a part of this invention and is more fully described in copending patent application Ser. No. 463,192 filed on even date herewith, invented by Randall P. Buhk, assigned to the assignee of this application, and incorporated herein by reference. Basically, the support includes a pair of spaced side rails 30 joined to the ends of a stretcher 20 which is in turn supported on a spindle type base 10. The side rails 30 are tubular steel members welded to the ends of the struts 22 and 23 of stamped steel stretcher 20.

Supporting seat 40 includes a channel 41 at each side thereof which fits over and seats on the side rails 30 of the frame assembly. Similarly, supporting back 50 includes a channel 51 at each side thereof for fitting over and seating on the back supporting portions of side rails 30.

The channels 41 which are formed at each side of seat 40 are raised generally with respect to the rest of seat 40 so as to define a well 42 between the spaced channels 41 (FIG. 5). It is not essential that the entire surface of seat 40 be below the level of the tops of channel 41 (it will be noticed that seat 40 raises somewhat towards the middle) but it is preferable that there be a well-like depression at least in the area adjacent the side channels 41. In this manner, when the upholstered inner seat 60 is secured to supporting seat 40, its edges will be positioned fairly closely adjacent the inside wall of the raised channels 41 and it will be more difficult to get underneath the seat upholstery pad 60 and pry it upwardly. Inner seat 60 is approximately as wide as the distance between the inwardly facing walls of side channels 41 of supporting seat 40.

At the underside of seat 40, at each front corner of seat 40, each side channel 41 terminates in a recessed pocket 49 into which the forward end of side rail 30 extends (FIG. 6). This not only serves to hide the end of side rail 30, but also serves to secure supporting seat 40 in place at the front of the chair.

The channels 51 are formed at each side of back 50 so as to define a well 52 between the spaced channels 51 (FIG. 7). It is not essential that the entire surface of back 50 be below the level of the tops of channel 51, but it is preferable that there be a well-like depression at least in the area adjacent the side channels 51. In this manner. when the upholstered inner back 80 is secured to supporting back 50, its edges will be positioned fairly closely adjacent the inside wall of the raised channels 51 and it will be more difficult to get underneath the back upholstery pad 80 and pry it upwardly. Inner back 80 is approximately as wide as the distance between the inwardly facing walls of said channels 51 of supporting back 50.

At the backside of back 50, at each top corner of back 50, each side channel 51 terminates in a recessed pocket 59 into which the upper end of side rail 30 extends (FIG. 8). This not only serves to hide the end of side rail 30, but also serves to secure back 50 in place at the back of the chair.

The side channels 41 of seat 40 include projecting portions or seat channel projections 43 which project rearwardly and upwardly from the rear edge of seat 40 towards back 50 (FIGS. 4, 9, and 10). Similarly, the side channels 51 of back 50 include projecting portions or back channel projections 53 which project downwardly from the bottom of back 50 towards seat 40. Channel projection 43 terminates in a channel shaped flange 44 while channel projection 53 terminates in a channel shaped overlying flap 54. Flap 54 overlaps flange 44 so that the side channels 41 and 51 meet in such a way as to align channel projections 43 and 53 and to define a continuous, smooth flowing surface with only a slight line being visible at the junction. Once flap 54 is seated over flange 44, a screw is passed through a screw hole 540 in the inside of channel projection 53 (FIG. 9), above flap 54, and is threaded into underlying side rail 30. Similarly, a screw is passed through screwhole 44a in the inside of channel projection 43 and is threaded into underlying side rail 30. This positively locks supporting seat and supporting back 50 in place at their rear and bottom respectively so that once the ends of side rails 30 are in place in the pockets 49 and 59 of seat 40 and back 50 respectively and once the projecting side channel portions 43 and 53 are in their proper overlapping condition and secured by screws through hole 54a and 44a, the back 50 and seat 40 are firmly secured to side rails 30.

In assembly, the inner seat 60 and inner back 80 are covered with cushioning 71 and 91 respectively and upholstery 72 and 92 respectively, in the manner indicated above. The upholstered inner seat is then fitted onto the supporting seat with its front and rear lips 61 and 62 respectively matingly embracing the front and rear edges and 46 respectively of supporting seat 40. The integrally molded buttons 47 along the front edge 45 of seat 40 hook into the receiving holes or apertures 63 of front lip 61 of inner seat 60. Similarly, the integrally molded tabs 48 on the rear edge 46 of supporting seat 40 fit into the receiving slots 64 on rear lip 62 of inner seat 60. The upholstered inner back 80 similarly fits onto supporting back with its top and bottom lips 82 and 81 respectively matinglyv embracing the top and bottom edges 56 and respectively of supporting back 50. The projecting buttons 57 and 58 on supporting back 50 hook into the holes 83 and 84 respectively along the bottom lip 81 and top lip 82 respectively of inner back 80. The supporting seat 40 and supporting back 50 are then secured to the side rails 30 of the supporting frame in the manner indicated above.

Of course, it is understood that the above is merely a preferred embodiment of the invention in that various changes and alterations can be made without departing from the spirit and broad aspects of the invention as set forth in the attached claims. 3

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A chair comprising: a formed, plastic supporting seat and back means; a* formed plastic inner seat and back means having a configuration conforming generally to that of said supporting seat and back means; support means for supporting said supporting seat and back means; said supporting seat and back means including at least a front edge along the front of the seat portion thereof and a top edge along the top of the back portion thereof; said inner seat and back means including at least a front lip along the front of the seat portion thereof extending over and matingly embracing said front edge of said supporting seat and back means and a top lip along the top of the back portion thereof extending over and matingly embracing said top edge of said supporting seat and back means; one of said front lip and said front edge including at least one projection integrally molded thereto and projecting therefrom, the other of said front lip and said front edge including an integrally molded receiving aperture adapted to matingly receive said projection; and one of said top lip and said top edge including at least one projection integrally molded therewith and projecting therefrom and the other including an integrally molded receiving aperture adapted to receive said projecting whereby said inner seat and back means are secured to said supporting seat and back means.

2. The chair of claim 1 in which upholstery means I cover said inner seat and back means; said inner seat and back means having sufficient thickness and rigidity to hold their shape' during the upholstery covering process and to hold their shape when secured to said supporting seat and back means, and said inner seat and back means having sufficient resilient flexibility that said front and top lips can be snapped over said front and top edges of said supporting seat and back means.

3. The chair of claim 2 in which said supporting seat and back means comprises a separate supporting seat and a separate supporting back; said inner seat and back means comprising a separate inner seat and a separate inner back; said supporting seat including a rear edge and said inner seat including a rear lip, said rear lip fitting over and matingly embracing said rear edge; one of said rear lip and said rear edge on said inner seat and supporting seat respectively including at least one projection integrally molded therewith and projecting therefrom, the other of said rear lip and rear edge including a receiving aperture adapted to matingly receive said projection; said supporting back including a bottom edge and said inner back including a bottom lip, said bottom lip fitting over and matingly embracing said bottom edge; one of said bottom lip and said bottom edge on said inner back and said supporting back respectively including a projection integrally molded therewith and projecting therefrom, the other of said bottom lip and bottom edge including an aperture adapted to matingly receive said projection.

4. The chair of claim 3 in which each of said projections is'located on and integrally molded with said supporting seat and back means and each of said apertures is located inand integrally molded with said inner seat and back means.

5. The chair of claim 4 in which said projections on said front edge of said supporting seat and on said top and bottom edges of said supporting back comprise buttons having posts with enlarged heads on the ends of said posts, said enlarged heads hooking into their respective receiving apertures on the front lip of said inner seat and on, the bottom and top lips of said inner back; said projection on said rear edge of said supporting seat comprising at least one tab projecting therefrom, said receiving aperture on said rear lip of said seat comprising aslot in which said tab is received.

6. The chair of claim 4 in which each of said projections is located on the mold parting line of its respective supporting seat and supporting back whereby said projections can be integrally molded to said supporting seat and back without the need for special cams in the mold.

v7. The chair of claim 1 in which said projections comprise buttons having a post with an enlarged head on the end thereof, said enlarged head hooking into its respective receiving aperture.

8. The chair of claim 1 in which said projections are located on said supporting seat and back means and said apertures are located on said inner seat and back means.

9. The chair of claim 1 in which each of said projections is located on the parting line of its respective seat and back means and inner seat and back means whereby said projections can be integrally molded with their respective supporting seat and back means and inner seat and back means without the need for employing cams in the mold.

10. The chair of claim 3 in which said support means comprises a base. a stretcher operably mounted on said base and a pair of spaced side rails joined to said stretcher; said supporting seat and said supporting back each including a channel at each side thereof with each side channel being seated over one of said side rails; said bottom edge of said supporting back being spaced from said rear edge of said supporting seat; each of said side channels of said supporting back including projection portions extending downwardly said supporting seat and each of said side channel lips and supporting seat including projection portions extending upwardly toward said supporting back; one of said supporting seat channel projection portions and supporting back channel projection portions overlapping the other of said channel'projection portions at each side of said chair; securing means securing at least the overlapping one of said channel projection portions to said side rail at each side of said chair whereby said supporting seat and supporting back members are secured to said side rails generally at said overlapping channel portions.

11. A ehair comprising: a base, a stretcher operably mounted on said base; a pair of spaced side rails joined to said stretcher, each said side rail having a seat supporting portion and a back supporting portion; a formed plastic supporting seat and a formed plastic supporting back; a formed plastic inner seat having a shape conforming generally to the face of said supporting seat and a formed plastic inner back having a shape conforming generally to the face of said supporting back; seat upholstery covering means covering the face of said inner seat and being wrapped around the edges thereof to the rear surface thereof; back upholstery covering means covering the face of said inner back and being wrapped around the edges thereof to the rear surface thereof; one of said supporting seat and said supporting back including a flange at least at each side thereof adjacent one of said side rails. said flange being seated on its respective side rail; the other of said supporting seat and said supporting back including a flap at least at each side thereof overlapping said flange; securing means securing at least said other of said supporting seat and said supporting back to said side rail in the vicinity of said flap whereby said supporting seat and said supporting back are secured to said side rails at said overlapping flap and flange portions.

12. The chair ofclaim 11 in which there is a space between said supporting seat and said supporting back; said supporting seat including a projection channel projecting rearwardly and upwardly therefrom generally at each rear corner thereof and being seated over its respective side rails, said back including a projection channel projecting downwardly therefrom at each lower corner thereof and being seated over its respective side rail; said flange comprising one of each said seat projection channels and said back projection channels including a flange; said flap comprising each of the other of said seat projection channels and said back projection channels including a flap. each said flap fitting over each said flange to provide a flush overlap thereof.

13. The chair of claim 12 in which said securing means comprises a fastener threaded through at least one of each of said seat projection channels and back projection channels and into its respective side rail. 

1. A chair comprising: a formed, plastic supporting seat and back means; a formed plastic inner seat and back means having a configuration conforming generally to that of said supporting seat and back means; support means for supporting said supporting seat and back means; said supporting seat and back means including at least a front edge along the front of the seat portion thereof and a top edge along the top of the back portion thereof; said inner seat and back means including at least a front lip along the front of the seat portion thereof extending over and matingly embracing said front edge of said supporting seat and back means and a top lip along the top of the back portion thereof exteNding over and matingly embracing said top edge of said supporting seat and back means; one of said front lip and said front edge including at least one projection integrally molded thereto and projecting therefrom, the other of said front lip and said front edge including an integrally molded receiving aperture adapted to matingly receive said projection; and one of said top lip and said top edge including at least one projection integrally molded therewith and projecting therefrom and the other including an integrally molded receiving aperture adapted to receive said projecting whereby said inner seat and back means are secured to said supporting seat and back means.
 2. The chair of claim 1 in which upholstery means cover said inner seat and back means; said inner seat and back means having sufficient thickness and rigidity to hold their shape during the upholstery covering process and to hold their shape when secured to said supporting seat and back means, and said inner seat and back means having sufficient resilient flexibility that said front and top lips can be snapped over said front and top edges of said supporting seat and back means.
 3. The chair of claim 2 in which said supporting seat and back means comprises a separate supporting seat and a separate supporting back; said inner seat and back means comprising a separate inner seat and a separate inner back; said supporting seat including a rear edge and said inner seat including a rear lip, said rear lip fitting over and matingly embracing said rear edge; one of said rear lip and said rear edge on said inner seat and supporting seat respectively including at least one projection integrally molded therewith and projecting therefrom, the other of said rear lip and rear edge including a receiving aperture adapted to matingly receive said projection; said supporting back including a bottom edge and said inner back including a bottom lip, said bottom lip fitting over and matingly embracing said bottom edge; one of said bottom lip and said bottom edge on said inner back and said supporting back respectively including a projection integrally molded therewith and projecting therefrom, the other of said bottom lip and bottom edge including an aperture adapted to matingly receive said projection.
 4. The chair of claim 3 in which each of said projections is located on and integrally molded with said supporting seat and back means and each of said apertures is located in and integrally molded with said inner seat and back means.
 5. The chair of claim 4 in which said projections on said front edge of said supporting seat and on said top and bottom edges of said supporting back comprise buttons having posts with enlarged heads on the ends of said posts, said enlarged heads hooking into their respective receiving apertures on the front lip of said inner seat and on the bottom and top lips of said inner back; said projection on said rear edge of said supporting seat comprising at least one tab projecting therefrom, said receiving aperture on said rear lip of said seat comprising a slot in which said tab is received.
 6. The chair of claim 4 in which each of said projections is located on the mold parting line of its respective supporting seat and supporting back whereby said projections can be integrally molded to said supporting seat and back without the need for special cams in the mold.
 7. The chair of claim 1 in which said projections comprise buttons having a post with an enlarged head on the end thereof, said enlarged head hooking into its respective receiving aperture.
 8. The chair of claim 1 in which said projections are located on said supporting seat and back means and said apertures are located on said inner seat and back means.
 9. The chair of claim 1 in which each of said projections is located on the parting line of its respective seat and back means and inner seat and back means whereby said projections can be integrally molded with their respective supporting seat and back meaNs and inner seat and back means without the need for employing cams in the mold.
 10. The chair of claim 3 in which said support means comprises a base, a stretcher operably mounted on said base and a pair of spaced side rails joined to said stretcher; said supporting seat and said supporting back each including a channel at each side thereof with each side channel being seated over one of said side rails; said bottom edge of said supporting back being spaced from said rear edge of said supporting seat; each of said side channels of said supporting back including projection portions extending downwardly said supporting seat and each of said side channel lips and supporting seat including projection portions extending upwardly toward said supporting back; one of said supporting seat channel projection portions and supporting back channel projection portions overlapping the other of said channel projection portions at each side of said chair; securing means securing at least the overlapping one of said channel projection portions to said side rail at each side of said chair whereby said supporting seat and supporting back members are secured to said side rails generally at said overlapping channel portions.
 11. A chair comprising: a base, a stretcher operably mounted on said base; a pair of spaced side rails joined to said stretcher, each said side rail having a seat supporting portion and a back supporting portion; a formed plastic supporting seat and a formed plastic supporting back; a formed plastic inner seat having a shape conforming generally to the face of said supporting seat and a formed plastic inner back having a shape conforming generally to the face of said supporting back; seat upholstery covering means covering the face of said inner seat and being wrapped around the edges thereof to the rear surface thereof; back upholstery covering means covering the face of said inner back and being wrapped around the edges thereof to the rear surface thereof; one of said supporting seat and said supporting back including a flange at least at each side thereof adjacent one of said side rails, said flange being seated on its respective side rail; the other of said supporting seat and said supporting back including a flap at least at each side thereof overlapping said flange; securing means securing at least said other of said supporting seat and said supporting back to said side rail in the vicinity of said flap whereby said supporting seat and said supporting back are secured to said side rails at said overlapping flap and flange portions.
 12. The chair of claim 11 in which there is a space between said supporting seat and said supporting back; said supporting seat including a projection channel projecting rearwardly and upwardly therefrom generally at each rear corner thereof and being seated over its respective side rails, said back including a projection channel projecting downwardly therefrom at each lower corner thereof and being seated over its respective side rail; said flange comprising one of each said seat projection channels and said back projection channels including a flange; said flap comprising each of the other of said seat projection channels and said back projection channels including a flap, each said flap fitting over each said flange to provide a flush overlap thereof.
 13. The chair of claim 12 in which said securing means comprises a fastener threaded through at least one of each of said seat projection channels and back projection channels and into its respective side rail. 